실데나필

혈관 확장제 - 제5형 포스포디에스테라제 (PDE5) 억제제

실데나필은 강력한 **제5형 포스포디에스테라제(PDE5) 억제제**입니다. 인의에서는 주로 발기부전 치료제로 알려져 있지만, 수의 약리학에서는 **폐동맥 고혈압(PH)** 치료의 핵심 약물입니다. * **임상 요점**: 만성 이첨판 질환, 심장사상충증 또는 원발성 폐질환(예: 폐섬유증)으로 인해 폐동맥 고혈압이 발생한 개와 고양이에게 특히 효과적입니다. * 폐동맥 혈관상을 선택적으로 확장시킴으로써 우심실 후부하를 크게 감소시키고, 실신, 운동 불내성 및 우측 울혈성 심부전과 같은 임상 증상을 개선합니다. * 폐혈관에 대한 특이성이 높아, 다른 혈관 확장제와 병용하지 않는 한 일반적으로 심각한 전신성 저혈압을 유발하지 않습니다.

작용 기전: Sildenafil exerts its effects via the **nitric oxide (NO) pathway** in smooth muscle cells: * Endothelial cells release **Nitric Oxide (NO)** → activates the enzyme **guanylate cyclase** → converts GTP to **cyclic guanosine monophosphate (cGMP)**. * **cGMP** acts as a secondary messenger causing smooth muscle relaxation and vasodilation. * **PDE5** is the enzyme responsible for degrading cGMP, and it is found in high concentrations in the pulmonary vasculature and corpus cavernosum. * **Mechanism**: Sildenafil competitively inhibits **PDE5** → prevents cGMP breakdown → intracellular cGMP accumulates → resulting in prolonged and enhanced **NO-mediated pulmonary vasodilation**.

동물 종별 용량

Cats

Moderate to severe PH secondary to either left heart disease or primary lung disease · 1 mg/kg · PO · q8h
Pulmonary arterial hypertension · 1.6 mg/kg · PO · q12h · Reported dose tolerated and clinically efficacious.

Dogs

Pulmonary hypertension · 1.9 mg/kg (range from 0.5-2.7 mg/kg) · PO · q8-24h · Median dose from a retrospective study. Dogs may have been also treated with oxygen, ACE inhibitors, furosemide, amlodipine, diltiazem, theophylline, phenobarbital and/or antibiotics.
Pulmonary hypertension documented by Doppler, chronic pulmonary disease, right-sided heart failure (HW disease; congenital) · 0.5-1 mg/kg (higher dose of 2 -3 mg/kg three times a day may be tolerated and needed) · PO · two times daily
Moderate to severe PH secondary to either left heart disease or primary lung disease · 1 mg/kg · PO · q8h
Pulmonary hypertension · 1-2 mg/kg · PO · three times daily
Pulmonary arterial hypertension · 0.5-2.7 mg/kg (suggested median dose from clinical studies is 3 mg/kg/day) · PO · q8-24h · Improves quality of life despite lack of significant echocardiographic reduction in pressures.

용량은 면허 수의 전문가를 위한 임상 참고 자료입니다. 항상 최신 라벨과 개별 환자에 대해 확인하십시오.

투여 경로

POIV

금기

Concurrent use with organic nitrates
Known hypersensitivity to sildenafil
Pulmonary veno-occlusive disease (PVOD)
Systemic hypotension
Significant hepatic impairment
Significant renal impairment
Bleeding disorders
Concurrent use of nitrates

이상반응

Cutaneous flushing of the inguinal region
Gastrointestinal effects (possible)
Headache, visual disturbances, dyspepsia, nasal congestion, myalgia, priapism, dizziness, and back pain (reported in humans)
Vomiting
Dizziness / weakness
Raised intraocular pressure
Systemic hypotension (especially if combined with other vasodilators)

약물 상호작용

Alpha-adrenergic blockers (e.g., phentolamine, phenothiazines, phenoxybenzamine) · May increase hypotensive effects
Amlodipine · Potential to increase hypotensive effects
Antihypertensive, hypotensive drugs · Potentially could increase hypotensive effects
Azole antifungals (ketoconazole, itraconazole) · May reduce sildenafil metabolism and increase AUC
Cimetidine · May reduce sildenafil metabolism and increase AUC · moderate
Erythromycin, Clarithromycin · May reduce sildenafil metabolism and increase AUC
Heparin · May increase bleeding risks
Nitrates (e.g., NTG, Isosorbide) · Significant potentiation of vasodilatory effects; life-threatening hypotension possible
Nitroprusside sodium · Significant potentiation of vasodilatory effects; life-threatening hypotension possible
Phenobarbital · May decrease sildenafil concentrations · moderate
Rifampin · May decrease sildenafil concentrations
Erythromycin · Increases plasma sildenafil concentration · moderate
Itraconazole · Increases plasma sildenafil concentration · moderate

모니터링

Clinical efficacy (improved syncope, cough, respiratory effort)
Pulmonary artery pressure
Systemic blood pressure
Adverse effects
Clinical signs of pulmonary hypertension (exercise tolerance, syncope, respiratory rate/effort)
Echocardiography (to monitor right heart function and pulmonary pressures)
Intraocular pressure (if pre-existing ocular disease)

과용량

Little information is available in veterinary species. In humans, massive overdose (2000 mg) resulted in tachycardia, nonspecific ST-T changes on ECG, headache, dizziness, and flushing. It is expected that overdoses in animals would mirror the drug's adverse effect profile (e.g., profound hypotension, tachycardia, cutaneous flushing). **Treat supportively.**

VetSheet 약물 레퍼런스는 면허 수의 전문가를 위한 임상 의사결정 보조 도구이며, 전문적 판단이나 제조사의 최신 라벨을 대신하지 않습니다.